JPS63123729A - Paper sheet feeder - Google Patents

Abstract

PURPOSE:To prevent the occurrence of the feed of sheets in a superposed state and wrinkling, by a method wherein, during the feed of sheets by means of feed rollers, a gap is provided between a subsequent sheet on a hopper plate and a pick roller. CONSTITUTION:When a sheet 15 is conveyed to feed roller 13 and 14, levers 4 and 4' are pressed by means of the end parts in he direction of the long size of cams 3 and 3', and resultantly a hopper plate release cover 5 is depressed. Thus, a hopper plate 6 is pressed against the resilient force of a coil spring 8, and as a result, a gap is provided between pick rollers 1 and 1' and a subsequent sheet. With this state, the pick rollers 1 and 1' are stopped. Thus, the sheet 15 conveyed to feed roller 13 and 14 at a current time is further conveyed but since no load is applied on the pick rollers 1 and 1', smooth conveyance of the sheet 15 is effected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a paper feeding device in a hopper section of an electrophotographic printer device or a hopper section of a sheet feeder of a serial printer device.

[Prior Art] Conventionally, in paper feeding devices such as sheet feeders that separate and take out sheets one by one from a stack of sheets, the sheets are pressed against a cylindrical roller, and the sheets are separated into one sheet by friction between the separating claw and the sheets. Each piece is separated.

FIG. 3 shows its configuration. That is, the paper 23 is sandwiched between the pick roller 21 and the plate 22,
A coil spring 24 presses the paper 23 against the pick roller 21 from below.

When the pick roller 21 is rotated, only one sheet of paper 23 is separated by the separation claw 25, and the feed roller 26, 27
sent to.

[Problems to be solved] In the conventional paper feeding device described above, the feed port 26.2
The paper 23 that has been fed up to 7 is pulled by the rotational force of the feed rollers 26 and 27. At this time, the pick roller 21
Although the driving force that rotates the paper 23 is cut off, when the paper 23 is fed by the feed rollers 26 and 27, the coil spring 2
4 and the pick roller 21, the sheets of paper slide against each other, and tension is generated in the bound paper 23. This tension disappears the moment the trailing edge of paper 23 leaves feed rollers 26,27. This variation in tension may cause slight unevenness in paper feeding, which may adversely affect the print quality of the printer.

In order to solve this problem, a mechanism has been devised in which a mechanism is provided to release the pressure of the coil spring 24 to reduce changes in tension during paper feeding. One of these is one in which the paper is separated by a semicircular roller and sent to a feed roller, and the paper underneath is held down by a fixed separation claw.

However, if the separating claws are fixed and holding down the paper, the paper cannot be separated properly, and double feeding and wrinkles due to the claws are likely to occur.

Therefore, an object of the present invention is to provide a paper feeding device that can smoothly feed paper without causing double feeding, wrinkles, etc.

[Means for Solving Problems] A paper feeding device of the present invention that solves the above conventional problems includes a hopper plate on which a plurality of sheets are stacked, and a pick for taking out the sheets stacked on the hopper plate one by one. a feed roller that conveys the paper taken out by the pick roller; a spring mechanism that presses the paper on the hopper plate against the feed roller; A rotating cam mechanism is used to move the hopper plate up and down in conjunction with the cam mechanism, and when the paper is conveyed by the feed roller, a gap is created between the pick roller and the next paper on the hopper plate. The structure includes a hopper plate drive mechanism provided.

[Examples] Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view showing the structure of a paper feeding device according to an embodiment of the present invention, and FIG. 2 is a perspective view thereof.

In the figure, 1 and 1 degrees indicate pick rollers each formed in a semicircular shape, and both are fixed to the drive shaft 2. Further, elliptical cams 3 and 3° are fixed to the drive shaft 2 on both sides of the pick rollers 1 and 1°, respectively. Each of these cams 3, 3' is bent into an L-shape, and one end of a lever 4.4' which is slightly rotatable about the bent portion 4a comes into contact with the cams 3, 3'. The other ends of these levers 4 and 4° are connected by a hopper plate release bar 5. The hopper plate release bar 5 is connected to the tip of a hopper plate 6, which is placed below the pick roller 1.1'' and on which a large number of sheets of paper 15 are stacked. It moves up and down slightly in conjunction with the

The hopper plate 6 is pressed from below by the coil spring 8, which causes the paper 15 to be pushed onto the pick rollers 1, 1'.
It is designed to be pressed against Further, the drive shaft 2 is rotationally driven by a drive motor 12 via a gear mechanism 11 . A spring clutch 9 is attached to the drive shaft 2, and the spring clutch 9 stops the pick rollers 1, 1' so that the string portions and the ends of the cams 3, 3' in the longitudinal direction are downward. A clutch solenoid 10 is arranged opposite to this spring clutch 9.

Note that 13 and 14 are feed rollers for conveying the paper 15 taken out by the pick rollers 1 and 1'.

Next, the operation of the paper feeding device of the present invention having the above configuration will be explained. First, when the paper 15 is taken out from the hopper plate 6, the clutch solenoid 10 is driven, the spring clutch 9 is released, and the rotational force of the drive motor 12 is transmitted to the drive shaft 2 via the gear mechanism 11.

This rotation of the drive shaft 2 causes the cams 3, 3' to rotate half a turn from the state shown in FIG. The paper 15 separated from the hopper plate 6 by the separating claw 7 is taken out. The paper 15 taken out by the pick rollers 1 and 1° is fed to the feed roller 13° and 14 parts.

Next, the drive shaft 2 rotates further, and as shown in FIG.
When the hopper plate release bar 5 is fed to the 14th part, the lever 4.4° is pushed by the end of the cam 3; For this reason,
The hopper plate 6 is pressed against the elastic force of the coil spring 8, and as a result, a gap is created between the pick rollers 1, 1' and the next sheet 15. In this state, pick roller 1
, 1' are stopped. Therefore, at this time, the sheet 15 that has been fed to the feed rollers 13 and 14 is further conveyed, but since no load is applied by the pick roller 1.1', the sheet 15 is conveyed smoothly.

[Effects of the Invention] As described above, the paper feeding device of the present invention is provided with a cam mechanism on the drive shaft of the semicircular pick roller, and in conjunction with this cam mechanism, the hopper plate on which sheets are stacked can be moved up and down. Since the paper is conveyed by the feed roller, a gap is created between the next sheet on the hopper plate and the pick roller, so the sheet can be conveyed without any load being applied to it, and it is possible to prevent double feeding, wrinkles, etc. This has the effect of preventing this occurrence and allowing smooth paper feeding.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the configuration of a paper feeding device according to an embodiment of the present invention, FIG. 2 is a perspective view of the same, and FIG. 3 is a side view showing a conventional paper feeding device. 1.1°: Pick roller 2: Drive shaft 3.3°: Cam 4.4' Nilever 6: Hopper plate 7: Separation claw 8: Coil spring 9 Spring clutch 10: Clutch solenoid 11: Gear mechanism 12: Drive motor 13.14: Feed roller

Claims (1)

[Claims] A hopper plate on which a plurality of sheets are stacked, a pick roller that takes out the sheets stacked on the hopper plate one by one, a feed roller that conveys the sheets picked up by the pick roller, and a feed roller that transports the sheets picked up by the pick roller, and a a spring mechanism that presses the paper against the feed roller; a cam mechanism that is provided coaxially with the pick roller and rotates together with the pick roller; and a cam mechanism that drives the hopper plate up and down in conjunction with the cam mechanism, and A paper feeding device comprising: a hopper plate drive mechanism that creates a gap between the pick roller and the next paper on the hopper plate when the paper is conveyed by the roller.